Method for the automated analysis of a mobile radio telephone system

ABSTRACT

The invention relates to a method for the automated analysis and appraisal of a mobile radio telephone system ( 1 ). Said method scans calls that are executed as part of a test phase, in accordance with internal and external system parameter values which flag error conditions (e.g. handover errors) or system performance deficiencies (e.g. poor voice quality during transmission). In a subsequent step, the parameters are evaluated in several modules ( 12.1–12.3 ) according to selectable grouping criteria, whereby for each module a multitude of relevant events or event sequences are examined and a module quality value ( 17.1–17.3 ) is determined with regard to a specific appraisal criterion. The system quality value ( 20 ) of the entire system is calculated as a weighted sum of the quality values from the individual modules and can be displayed graphically as a comparison of all groups, with regard to the chosen grouping criterion.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/CH00/00376 which has an Internationalfiling date of Jul. 11, 2000, which designated the United States ofAmerica.

TECHNICAL FIELD

The invention relates to a method for the automated analysis of a mobileradio telephone system, in which method a multiplicity of testconnections are established between two terminals, particularly a mobileterminal and a stationary or mobile terminal, as part of a test phase,and a plurality of protocol parameter values are acquired during thetest phase.

PRIOR ART

The providers of mobile telecommunication are increasingly exposed tocompetition. There is a corresponding need to control and, if possible,to improve the quality of their own mobile radio telephone system. Onthe one hand, this involves opening up new geographic regions asefficiently as possible (i.e. at low cost but with area-wide coverage)in order to increase the potential of interested parties in this way. Onthe other hand, the existing customers should be kept by means of highquality of the network.

From the point of view of the user, the quality of the mobile radiotelephone system is judged on the transmission quality of the voice, theavailability of the network access, the frequency of call interruptionsetc., i.e. the user wishes to be able to telephone at any time and tohave a good and uninterrupted connection independently of his locationand the duration of the call.

Mobile radio telephone systems are highly complex technically. Theirperformance depends on boundary conditions which vary with time and insome cases can only be calculated with difficulty or not at all. Inaddition, a mobile radio telephone system must be continually adapted tothe current needs (e.g. by integrating more base stations). Faults andweak points in the system must be localized step by step and the causesmust be eliminated. However, the operator of the mobile radio telephonesystem cannot rely on the reports from the subscribers. They willscarcely take the trouble to point out possible weak points to thesystem operator in a consistent and logical manner. Even if the operatorwere to be informed in this way, these reports would only in exceptionalcases be suitable for locating a system fault. There would be too littleinformation available about the system state which could have caused thefault which led to the complaint.

Today, system analysis and optimization must be performed in painstakingand detailed work by experts. The problem is that errors in systemprogramming, malfunctions of the hardware and design faults in thenetwork planning have effects on the subjectively perceived networkquality which are difficult to predict.

In the known manual analysis, many test connections are established andassessed with respect to quality. To be able to locate any disturbancesin the system, protocol data are recorded and stored. Such test runs areperformed periodically in most cases. The test duration can be selectedarbitrarily and thus an enormous effort must be made not only incollecting the test data but also in evaluating the collected data.

If it is considered that typically far more than 100 protocol values areproduced per second, it becomes clear how much effort is required tocheck all these values manually and to locate possible system faults(which—as already mentioned—are not necessarily apparent directly fromthe protocol values). There is no question of a systematic systemanalysis.

In WO 93/15591, a method for planning a cellular radio telephone networkis described. The planning is done on the basis of a model of the radioenvironment and of a simulation of the system. The aim of the simulationis to generate the data required for the subsequent analysis. It shouldalso be possible to apply the optimization of the system parameters toexisting systems and the parameters are then measured. As part of theevaluation, individual parameters are graphically displayed on a screenas a function of other parameters.

DESCRIPTION OF THE INVENTION

It is the object of the invention to specify a method of the typeinitially mentioned which provides for the automated analysis andassessment of the quality of a mobile radio telephone system.

The features of claim 1 define how this object is achieved. The methodaccordingly comprises the following steps:

-   -   a) A multiplicity of test connections is established between two        terminals (particularly a mobile terminal and a stationary        terminal or two mobile terminals) with the aid of a test and        measuring device as part of a test phase. In this context, a        test connection is considered to be established not only when it        is set up and dropped again (properly or due to faults) but also        if it is not established in spite of an attempt (is        unsuccessful, as it were).    -   b) During the test phase, the values of a plurality of protocol        parameters internal and external to the system are acquired and        recorded. For example, the parameter values of the various        system units are acquired separately during the data        acquisition. System units are understood to be functional units        (hardware components or also program units) of the mobile radio        telephone system and of the measuring device (e.g. various        layers in the terminals, switching units and other components of        the base stations, etc.).    -   c) From these protocol parameter values, records are generated        which are stored in real time or off-line in a database. The        database has a suitable structure so that it is possible to        search for all protocol parameter values selected in the sense        of the subsequent method steps.    -   d) The protocol parameters are evaluated in each case separately        with regard to a certain assessment criterion with a separate        module, the number of such modules being greater than or equal        to one and freely selectable. In most cases, a number of such        modules is provided. These assessment criteria can be, for        example, the type of call end, the speech quality or the degree        of coverage in the coverage area. The corresponding evaluation        modules for the assessment criteria mentioned are then called,        e.g., “call end analysis”, “speech quality analysis” and        “coverage analysis”.    -   e) Each module calculates a quality value—the module quality        value—of the mobile radio telephone system. For this purpose, a        further quality value—the event quality value—is determined for        a number of event types which are of significance for this        assessment criterion. The number of events taken into        consideration per module and also the number of parameters taken        into consideration per event is at least one, but can be        expanded arbitrarily. The module quality value is then        calculated as the mean value of the various event quality        values.    -   f) To obtain a quality value for the overall system, a system        quality value is calculated from the various module quality        values. It then becomes possible to subject the system to an        accurate analysis in order to analyze and to assess, for        example, the speech quality of the mobile radio telephone        system.

The core of the invention lies in the fact that the quality of variousparts and subsystems of the mobile radio telephone system issystematically determined. Systematically here means that apredetermined list of parameters and parameter sequences to be tested iscompletely processed. However, it means not only the quality ofindividual parameter values which are not within the prescribed intervaland may not even lead to a fault but also that of entire systemsequences, situations or circumstances which could result in systemerrors.

The essential advantage of the invention lies in the combination ofsystems and speed of analysis. Due to the enormous volume of data,technical experts would not only look for weeks but would alsofrequently become stuck because the search system cannot be guaranteedor only with disproportionately great expenditure.

Moreover, in contrast to the prior art, it is not only individualparameter values which are examined for correctness in the invention butentire sequences and the behavior of entire system parts or componentscan be analyzed. This makes it possible to better detect relationshipsand if possible to intervene more rapidly and more selectively. Thesystem analysis is of modular configuration which makes the methodextremely flexible and allows the system to be examined and to beassessed in every detail. If it is required, the system analysis canalso be followed by an automated fault correction, naturally.

The internal system protocol parameters mainly consist of signalingmessages which occur in the terminals or in the network (e.g. data whichare generated by the existing control hardware or software of the systemduring a call and are used for controlling and monitoring thecommunication link). The external system protocol parameters are mainlyinformation which is typically determined periodically or, if required,also by means of separate measuring and analysis methods in theterminals or distributed in the network (such as, e.g., data forassessing the quality of the connection, boundary information data onlocation, time, speed etc. of the mobile terminal).

Each record thus determined is provided with a time stamp and allocatedto a particular group of data on the basis of a grouping criterion (inmost cases allocated to a protocol parameter). A grouping criterion canbe, e.g., the base station, the geographic position (e.g. at 100 m), thefrequency channel or also the network operator. The data are stored in adatabase having a suitable structure.

The time stamp of the actual data acquisition and preferably anotherparameter, the identifier of the connection, are used for synchronizingthe data when they are input into the database. (The identifier is ofimportance especially if, in addition to the test connections, otheruser connections are also running via a particular unit, e.g. via a basestation.)

In a preprocessing step, the records can already be grouped inaccordance with a required grouping criterion as far as possible so thatthey can be processed better and more rapidly later. At the same time,the data reduction can also be performed.

Firstly, at least one event table per module is generated from therecords stored in the database by searching the database forpredetermined protocol parameter values or for certain combinations ofprotocol parameter values which signal a predefined event. Thecorresponding records (or, respectively, the protocol parameterscontained in them) are then stored wholly or partially in the eventtables.

For each event thus found, the exact time is determined at which it hastaken place. After that, a selectable or predefined leading and/ortrailing time is determined before or after the event, respectively,which identifies the period within which other relevant events arelocated which influence the event found or can be influenced by it.

The relevant data of the relevant events located within this leading ortrailing time are also picked out of the database and are entered in theevent table together with the data of the events found. Each event foundis classified by means of these data. The events are classified becausean event X which proceeds, e.g., event A is “normal” whereas event Xwhich is preceded by event B characterizes a fault and, accordingly,must be processed differently.

Once the events have been allocated to the respective classes, a qualityvalue—the event quality value—is determined for each possible event typeor event type which has occurred within the observation period.

-   -   a) For this purpose, a numerical value is firstly allocated to        each possible signaling message or sequence. This mapping of the        messages into the numerical domain takes place in order to        obtain a possibility for quantitative assessment of the        circumstances before and after a certain event.    -   b) After that, an average record is calculated from the records        of all events with the same classification and from these        numerical values, in each case forming the mean value of the        same protocol parameters of each data record or, respectively,        of the numerical values for the signaling sequences.    -   c) Using these mean values as components, an event vector is        formed for each possible event type (if at least one event of        this type has occurred).    -   d) The event quality value is now determined by scalar        multiplication of the event vector of a certain event type by a        weighting vector which corresponds to the event type, i.e. is        event-specific. This weighting vector is necessary since not all        protocol parameters of the event vector have the same amount of        influence or the same degree of significance for this event        type. The sum of the weighting factors of the individual event        weighting vectors is preferably equal to one so that, at the        same time, a certain normalization can also be achieved.

Finally, a system quality value with respect to a selectable groupingcriterion is also calculated from the individual module quality values.For this purpose, a quality vector is formed, the components of whichare the module quality values of the individual modules.

The system quality value is now calculated as the scalar product of thisvector by a module weighting vector which weights the individual modulesin dependence on the selected grouping criterion. The sum of thecomponents of the module weighting vector is one which also makes itpossible to achieve a normalization of the system quality value. Thisproduces a system quality value for each possible value of the groupingcriterion, i.e. exactly one system quality value for each base station,each geographic position, each frequency channel or each networkoperator.

It is thus possible to perform an evaluation of the acquired data whichis flexible, conforms to detail and has any degree of accuracy bysuitably selecting the event-specific vectors and the module weightingvectors. For example, it is possible to analyze the speech qualities ofthe connections of a particular base station in dependence on theterminal position or in dependence on the frequency channel used.

After the automated analysis of the mobile radio telephone system, thesystem quality values thus calculated can also be used for assessment ofthis system by a system engineer. To be able to perform the assessmentas simply as possible, these values are preferably displayedgraphically, for example as a histogram. In a diagram, the possibleelements of the selected grouping criterion (e.g. all base stations) areplotted along the x axis and the corresponding system quality values areplotted along the y axis. The elements can be arbitrarily sorted inaccordance with quality value or, for example in the case of frequencychannels, simply in ascending or descending order of the channel number.Diagrams with more than two dimensions can also be advantageous,however. For example, a three-dimensional diagram in the assessment ofquality with regard to the geographic position as group criterion.Instead of displaying the individual measurement positions along asingle axis (e.g. with the aid of a number), two of the three dimensionsof the diagram are simply used for displaying the measurement positionsat their correct positions. The system quality values are then displayedin the third dimension which conveys a three-dimensional impression ofthe system quality in the coverage area in a simple manner.

To be able to perform a more accurate system analysis, the systemquality values are related to one another with respect to variousgrouping criteria. For this purpose, for example, the same events of acertain class can be grouped in accordance with different groupingcriteria and then evaluated in accordance with the invention.

The external system parameters acquired are preferably the speechquality, the duration for establishing the connection, location, time,speed and direction of travel of the mobile station. The speech qualitycan be assessed in that a predetermined voice signal (e.g. a sentencespoken in various languages and/or with various voices) is transmittedand analyzed at the receiving end with the aid of a neuron network(compare e.g. EP-0 644 674 A2).

The method according to the invention is performed in a real environmentby means of an analysis arrangement in a conventional mobile radiotelephone system. This comprises a public mobile radio telephone networkand a plurality of terminals between which both normal telephoneconnections and test connections can be set up and ended again.Furthermore, at least one measuring device is provided by means of whichthe required protocol parameters can be acquired by measurement or byrecording system messages, there being typically a number of suchmeasuring devices. The parameters acquired are forwarded to anevaluating device which comprises a specifically structured database andan evaluating unit. The parameters are suitably stored in the databaseand after that analyzed by the evaluating unit with a plurality ofmodules in accordance with the method according to the invention andfrom this a system quality value is calculated. The time of transmissionof the acquired data from the measuring devices to the evaluatingdevice, and of the evaluation of the stored data, is open. Both can bedone both in real time and off-line at a later time.

According to the invention, the evaluation of the data acquired can alsotake place separately from the data acquisition. For this purpose, anevaluating device is used by means of which data previously acquired canbe imported. These data include, e.g., data acquired externally, i.e.measured and recorded at other locations, internal and/or externalsystem protocol parameters of an arbitrary mobile radio telephonesystem. These data already exist as records of selected protocolparameters or the records are formed by the evaluating device and storedin a suitably structured database. The records stored in the databaseare evaluated in accordance with the invention as described above.

To be able to perform the analysis of the mobile radio telephone systemmore and more precisely, additional parameters can be acquired and/orstored, new grouping criteria, events or event classes can be defined,other lead and lag times can be specified, other event vectors formed,the event-specific and/or the module weighting vectors can be changed oradditional or, respectively, other evaluation graphics can be generatedas required. Thus, the efficiency of the method according to theinvention can be increased further with time.

Further advantageous embodiments and combinations of features of theinvention can be obtained from the detailed description below and fromthe totality of patent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings used for explaining the exemplary embodiment show in:

FIG. 1 a diagrammatic representation of a mobile radio telephone systemand an arrangement for checking it;

FIG. 2 a block diagram for explaining the method according to theinvention;

FIG. 3 a diagrammatic, graphical representation of a possible systemanalysis;

FIG. 4 a diagrammatic, graphical representation of a further systemanalysis.

In principle, identical parts are provided with identical referencesymbols in the figures.

Approaches to Carrying Out the Invention

The exemplary embodiment described in the text which follows can beinterpreted as a multistage method:

At the beginning, the test connections are set up and the protocolparameters are acquired. In addition, the data are entered into arelational database and grouped in accordance with various groupingcriteria in a preprocessing step.

In a first step, the events of interest are picked out of the data,classified by means of the respective prior and subsequent history andassessed in accordance with the required evaluation. The events areprocessed in a number of modules which in each case determine the systemquality with respect to a particular criterion.

In a second step, a module quality value which reproduces the systemquality with respect to the corresponding criterion is calculated fromthe events assessed per module.

In a third step, a measure of the entire system quality with regard tothe selected grouping criterion is determined from the module qualityvalues.

In further steps, the system analysis is evaluated with respect to theselected grouping criterion in that the system quality of thecorresponding groups can be graphically displayed and thus compared withone another in a simple manner.

The object of the automatic analysis according to the invention is amobile radio telephone system of a type of design known per se. FIG. 1symbolically shows a mobile switching center 2 (MSC) and four basestations 3.1 to 3.4 (antennas). The base stations 3.1 to 3.4 arecontrolled, e.g., by two base station controllers 2.1, 2.2 (BSC) andsupply cells 4.1 to 4.4. The mobile radio telephone system is connected,for example, to a public network 1 (PSTN). Thus, calls can be made inthe usual manner between a stationary terminal 5.1 or a mobile terminal5.2, respectively, and a mobile station 6.

As a rule, it is very difficult to systematically measure and assess thequality of a mobile radio telephone system. Due to the fact that themobile station is continuously moving, the state of the mobile radiotelephone system is also changing. This takes place, however, notcontinuously but abruptly in some cases (e.g. during a handover due to achange to another base station).

On the market, specific measuring devices are already available whichallow calls to be set up automatically and the quality of the connectionto be measured (compare e.g. Ascom Infrasys AG, CH-4503 Solothurn,Switzerland “ascom Qvoice, The Most Advanced Cellular Network QualityMeasurement System”). Although these known measuring systems acquire alarge volume of data, they do not, however, provide the operator with apossibility for automated analysis and quality assessment.

The method according to the invention goes one step further in thiscase. The essential steps will be explained in greater detail withreference to FIGS. 1 and 2.

As part of a test phase, a large number of test connections are set upin succession and alternately between a stationary unit 9.1 (whichcomprises a first measuring device 7.1 and a conventional circuit of aterminal 5.1) and a mobile station 6 (which contains a second measuringdevice 7.3 with a mobile radio telephone circuit 5.3) or between amobile unit 9.2 (which comprises a third measuring device 7.2 and aconventional circuit of a mobile terminal 5.2) and the mobile station 6.In real terms, this means that, e.g., the mobile station 6 dials thenumber of the terminal 5.1 or 5.2, a check is made whether theconnection has been set up and after what time, that the speech qualityis measured and that, finally, the call is correctly terminated. Theprocedure is also carried out in the reverse direction, i.e. from unit9.1 or unit 9.2 to the mobile station 6. Several hundred connections arepreferably set up, dropped and measured by the measuring devices 7.1 to7.3, for example.

During this process, the mobile station is driven all over the area ofthe mobile radio telephone system to be tested.

Each of these calls is logged. I.e., all internal states of the mobileradio telephone system are stored, if possible, on the one hand and, onthe other hand, various external system parameters are also acquired.The states of the mobile radio telephone system are determined byinternal system protocol parameters. These parameters exist in everymobile radio telephone system (compare GSM Recommendation 04.08).Examples of these are:

-   -   Radio channel parameter (frequency, signal level etc.)    -   Call control parameters    -   Mobility management parameters (routing, handover parameters        etc.)

It is not only the protocol parameters occurring in the terminals (e.g.GSM protocols of various layers) which are acquired but also thosegenerated within the system, e.g. the protocols running in the basestations or controllers, respectively.

External system protocol parameters are those which are not generated bythe mobile radio telephone system itself such as, e.g.:

-   -   Coordination parameters (location, time, speed, direction etc.        of the mobile station),    -   Quality parameters (duration of the call set-up, unsuccessful        call set-up, quality of the speech signals transmitted during        the call, particular disturbances etc.),    -   Control information (e.g. time of the signal which causes the        terminal to dial a particular connection).

It must be noted that protocol parameters are always related to aninstantaneous operating state. They can change their values in partduring a call or from one call to the next.

From the protocol parameters mentioned, records related to theindividual functional units are generated and provided with a timestamp. During the test phase, the records can be stored, for examplelocally, in the order in which they are generated. However, it is alsopossible to transmit the records directly to a processing station 10where they are entered in a database 11 and are correlated with oneanother. For this purpose, various tables which list the data blocks orrecords in accordance with predetermined grouping criteria are generatedin a preprocessing step. Thus, the records can be listed, for example inchronological order (with additional specification of the type of data,the identification number of the call etc.). Advantageously, a number oflists are provided in accordance with the search functions to be appliedlater. For example, the data blocks can be sorted in accordance with thegeographic location of the mobile station.

Next, the parameter values stored in the database 11 are processed andanalyzed in the processing unit 8.

This is done in various modules 12.1 to 12.3. Each module 12.1 to 12.3evaluates the data with regard to a certain assessment criterion.Examples of these are:

-   -   Call End,    -   Speech Quality,    -   Coverage,    -   Timing,    -   Handover,    -   Data Service.

For this purpose, a plurality of event tables 13.1 to 13.9 are generatedby searching in the presorted lists for certain events relevant to therespective assessment criterion. These events are identified bysearching for certain individual or particular combinations of protocolparameter values and storing the corresponding records in the eventtables 13.1 to 13.9.

Such an event is, e.g., a connection release, regular or premature. Aconnection release can be detected, e.g., with the aid of the internalsystem protocol parameters. In a mobile radio telephone system there areflags which provide information in this regard. However, there are alsoexternal system protocol parameters which make it possible to detect aconnection release (e.g. corresponding or missing response signals fromthe other subscriber station).

A handover can also be called an event, for example.

In the combined search, the object is in most cases unusual combinationsof parameter values which may point to a weakness in the systemperformance (e.g. a high signal level in combination with a high biterror rate). In the next step, the accurate time at which it has takenplace is determined for each event found. After that, further eventswhich may be of significance for the event found, e.g. can influence itor can be influenced by it, are searched for within a particular leadingand trailing time. Relevant data of these events, too, are stored in theevent tables 13.1 to 13.9.

Using the stored data, e.g. the order and the parameter values of theevents within the leading and trailing time of a particular event, thelatter is then classified, i.e. allocated to one of several possibletypes of event. This provides a number of event types which in each casehave occurred more or less frequently within the observation interval.

With regard to the grouping criterion selected or to be evaluated,respectively, there is for each of these event types a certain selectionof relevant protocol parameters and a certain event weighting vector15.1 to 15.9 by means of which a more or less great significance can begiven to the individual parameter values.

The mean value of each protocol parameter of this selection is thenformed so that, at the end, the result is exactly one average record14.1 to 14.9 per event type. Each value of this average record 14.1 to14.9 is thus equal to the average of all corresponding values of theevent records of a particular event type.

The further processing in the individual modules 12.1 to 12.3 isperformed by formation of a vector from the average records 14.1 to 14.9and scalar multiplication by the corresponding event weighting vector15.1 to 15.9. The result is one event quality value 16.1 to 16.9 eachper event type examined.

Finally, to determine the module quality value 17.1 to 17.3 of theindividual modules, the mean value of all event quality values 16.1 to16.3 for module 12.1, 16.4 to 16.6 for module 12.2 and 16.7 to 16.9 formodule 12.3, calculated in this module, is simply calculated.

Lastly, the system quality value 20 is calculated. For this purpose, amodule quality vector 18 is formed from the individual module qualityvalues 17.1 to 17.3 and is then subjected to a scalar multiplication bya module weighting vector 19.

Instead of calculating the average records 14.1 to 14.9 or,respectively, the module quality values 17.1 to 17.3 as mean values ofthe individual event records or, respectively, the event quality values16.1 to 16.9 in each case, these could naturally also be calculated as aweighted sum (similarly to the scalar product in the calculation of theevent quality values 16.1 to 16.9 and of the system quality value 20)and the sum of the respective weighting factors could also be selectedequal to one in each case.

In the text which follows, greatly simplified examples will illustratethe above general statements. It is assumed in each case that the phaseof data acquisition and the preprocessing is already concluded. Thus,the data must be analyzed and represented in the required manner so thata system engineer can interpret them in a simple manner. In addition, heshould be able to refine his analysis until he has reached the requireddepth of detail.

The mobile radio telephone system is analyzed automatically after thesystem engineer has told the system (e.g. by selecting a menu point on acomputer screen) which evaluation, i.e. which quality values withrespect to which grouping criteria and with which weighting vectors, hewould like to see. The system first determines the weighting factorscorresponding to the evaluation, then performs the analysisautomatically and displays the required evaluation graphically on thescreen.

FIG. 3 shows, for example, a (hypothetically assumed) frequencydistribution of the system quality values with respect to the groupingcriterion network operator. For each network operator NB1 to NB5, acolumn is shown the height of which corresponds to the system qualityvalue of this network operator NB1 to NB5. The values are ordered inaccordance with the number of network operator NB1 to NB5.

It must be noted that the frequency distribution shown is only one of anenormous number of possible frequency distributions with respect to thisgrouping criterion.

Depending on the choice of weighting factors of the event weightingvectors or of the module weighting vector, very detailed information canbe extracted from the database 11. In the text which follows, threeexamples of this are given. In each example, the data from the firstmodule 12.1 with respect to the assessment criterion call end, from thesecond module 12.2 with respect to speech quality and from the thirdmodule 12.3 with respect to coverage are evaluated. The protocolparameters taken into consideration and their sequences with respect tocall end are assumed to be, e.g., signal level, bit error rate, radiochannel and handover.

First example: both the weights of the event weighting vectors 15.1 to15.9 and those of the module weighting vector 19 are all greater thanzero. In this case, the frequency distribution of FIG. 3 shows acomparison of the qualities of the overall mobile radio telephonesystems of the individual network operators NB1 to NB5.

Second example: the weights of the event weighting vectors 15.1 to 15.9are all greater than zero but the weights of the module weighting vector19 are all zero except that for the call end module 12.1. The frequencydistribution of FIG. 3 shows in this case an overall comparison of thequalities of all call ends of the individual network operators NB1 toNB5.

Third example: all weights of the event weighting vectors 15.1 to 15.9are equal to zero except that for the signal level. All weights exceptthat for the call end module 12.1 of the module weighting vector 19 arealso equal to zero. The frequency distribution of FIG. 3 shows adetailed comparison of the quality of all call ends of the individualnetwork operators NB1 to NB5 which are attributable to too low a signallevel in this case.

It is clear that an immense amount of evaluations are possible due tothe plethora of conceivable weighting vectors. It is also possible,therefore, to have the assessment of a mobile radio telephone systemperformed automatically by an evaluating unit (not shown) and not toleave this to a system engineer by means of the graphicalrepresentations. The evaluating unit can send, for example, correctionmessages to the functional units affected or display a list of faultsfound via an output unit to the system engineer. He can then take therequired measures (e.g. replace a defective control circuit or loadcorrect configuration data or a correct program). It is also possiblefor the system engineer initially to act independently during theanalysis and then to be supported by the system in the refinement anderror localization.

FIG. 4 shows another frequency distribution (also hypotheticallyassumed) of the system quality values with respect to the groupingcriterion base station. For each base station BS1 to BS13, one column isshown the height of which corresponds to the system quality value ofthis base station BS1 to BS13. However, the values are not ordered inaccordance with the number of the base station BS1 to BS13 but inaccordance with the respective system quality value. This makes itpossible to see at a glance the distribution of the quality valuescorresponding to the required evaluation, what the general quality levellooks like and where improvements are urgently necessary.

Here, too, it holds true that the frequency distribution shown is onlyone possibility from an enormous selection of frequency distributionswhich is possible in accordance with the selected weighting vectors.

The examples chosen were deliberately very simple. However, it can beeasily seen that the method is quite generally suitable for an analysisand assessment of a mobile radio telephone system of any required detailand thus for uncovering fault causes and for automated locating ofsystem defects.

In summary it must be stated that the method according to the inventionand the corresponding arrangement make it possible to analyze a mobileradio telephone system and to assess its quality so that it can beselectively improved.

The invention has the following advantages:

-   -   In principle, the method is programmable and expandable. It can        grow with increasing level of knowledge of the system provider.        It is also possible to include new findings of the network        operator.    -   System analysis and any subsequent fault finding and elimination        of causes is very rapid. For each hour of a test run, the        analysis time is within the range of seconds (and not of hours).    -   It is possible to assess the quality of an entire system or of        any part thereof.    -   However, it is also possible to find individual problems in        individual connections even with a very large volume of data and        a very low error rate of the system.    -   All problems known to the experts are rapidly identified. New        problems which have never occurred before can be detected and        selectively examined manually.

1. A method for the automated analysis of a mobile radio telephonesystem, in which: a) a multiplicity of test connections are establishedbetween two terminals, particularly a mobile terminal and a stationaryor mobile terminal, as part of a test phase, and b) a plurality ofprotocol parameter values are acquired during the test phase,characterized in that c) selected protocol parameter values are storedas record in a database with a suitable structure, d) the storedprotocol parameter values are evaluated by means of a plurality ofmodules, a module being used for evaluating the protocol parametervalues with respect to an assessment criterion, e) for each module, amodule quality value is calculated as mean value of a plurality of eventquality values, the event quality values representing a measure ofquality for in each case one particular event type, f) a system qualityvalue is calculated from the module quality values for the analysis ofthe mobile radio telephone system.
 2. The method as claimed in claim 1,characterized in that the protocol parameters acquired comprise internaland/or external system protocol parameters, signaling messages beingconsidered to be internal system protocol parameters and values measuredfrom the outside being considered as external system protocolparameters.
 3. The method as claimed in claim 2, characterized in thatat least a speech quality, a duration for establishing the testconnection and location, time, speed and direction of movement of themobile terminal are acquired as external system protocol parameters. 4.The method as claimed in claim 1 or 2, characterized in that a record isprovided with a time stamp and allocated to a corresponding group ofrecords in accordance with a predetermined grouping criterion.
 5. Themethod as claimed in claim 4, characterized in that the system qualityvalues are correlated with one another with respect to various groupingcriteria.
 6. The method as claimed in claim 1, characterized in that,for each module, at least one event table is generated in that a searchis made in the database for predetermined protocol parameter valuesidentifying a particular event or for combinations of protocol parametervalues and the corresponding records are wholly or partially stored inthe event tables.
 7. The method as claimed in claim 6, characterized inthat, for each event found, the time and a selectable or predeterminedleading and/or trailing time is determined and, for these events,relevant data of other events located within the leading time andtrailing time are also picked out of the database, are stored in theevent tables and the events found are classified on the basis of thedata of these relevant events.
 8. The method as claimed in either ofclaims 6 and 7, characterized in that the event quality value iscalculated for an event in that a) a numerical value is allocated toeach signaling message or sequence of signaling messages, b) an averagerecord is calculated from the records of all events with the sameclassification in that a mean value is calculated for each protocolparameter value or, respectively, for each numerical value of thesignaling messages, c) an event vector is formed from the mean values ofthe average record for each event, and d) the event vector is subjectedto a scalar multiplication by a predetermined event-specific weightingvector.
 9. The method as claimed in claim 1, characterized in that thesystem quality value is calculated with respect to a grouping criterionby a scalar multiplication of a module quality vector, the components ofwhich are the module quality values of the individual modules, by amodule weighting vector, the module weighting vector being dependent onthe grouping criterion.
 10. The method as claimed in claim 1,characterized in that the system quality values are displayedgraphically, particularly as a histogram.
 11. An analysis arrangementfor carrying out the method as claimed in claim 1, characterized in thatthe analysis arrangement comprises a conventional, public mobile radiotelephone network, at least two terminals for establishing the testconnections, at least one measuring device for acquiring the protocolparameter values and an evaluating device with a database for storingselected protocol parameter values as records and an evaluating unit forevaluating the records, the evaluating unit exhibiting a number ofmodules for calculating in each case one module quality value withrespect to an assessment criterion as mean value of a plurality of eventquality values which in each case represent a measure of quality for aparticular event type, and means for calculating a system quality valueas weighted sum of the individual module quality values.
 12. Anevaluating device for an analysis arrangement as claimed in claim 11,characterized in that it comprises means for importing acquired protocolparameter values, means for storing selected protocol parameter valuesas records and an evaluating unit, the evaluating unit exhibiting anumber of modules for calculating in each case one module quality valuewith respect to an assessment criterion as mean value of a plurality ofevent quality values which in each case represent a measure of qualityfor a particular event type, and means for calculating a system qualityvalue as weighted sum of the individual module quality values.